Articulated tracked vehicles comprising a front vehicle unit and a rear vehicle unit controllably interconnected by means of a control coupling, wherein the vehicle comprises a driveline for driving the vehicle are known. The driveline comprises according to prior art a diesel engine, a gearbox connected to the diesel engine, distribution gear, and shaft gears for front and rear vehicle units, the shaft gears being arranged to distribute the power to the respective track of the vehicle. Such a driveline occupies relatively large space and is relatively heavy.
U.S. Pat. No. 6,880,651 B2 discloses an articulated tracked vehicle with a driveline system having a first driveline comprising a diesel engine arranged in the front vehicle unit and a second driveline comprising an electric motor/generator arranged in the rear vehicle unit. In the first driveline the diesel engine is arranged to drive a gear box which in turn is connected to a drop box arranged to drive a drive shaft being connected to the front shaft gear and rear shaft gear distributing the power to the respective track. In the second driveline the drive shaft is connected to the electric motor/generator, wherein the electric motor is arranged to be driven by means of energy from a battery pack or a capacitor such that the tracks may be driven by means of the electric motor. The first and second vehicle units may be disengaged wherein the respective vehicle unit may be driven by itself. Further the diesel engine and/or the electric motor may drive both vehicle units when the vehicle units are interconnected. A disadvantage with such a construction is that it occupies a lot of space due to among others double drivelines and is also relatively heavy. Further batteries or a corresponding energy source are required in order to energize the electric motor, which also occupies space.